In the construction trades, particularly carpentry, straight-edges are used extensively to mark the location for a cut or other operation to be performed on a work surface. It has been recognized that in many applications, it is advantageous to use the straight-edge on the surface as a guide for the saw or other tools. When such a straight edge is used to guide a power saw, for example, it is necessary that the straight-edge be held in position on the workpiece.
For smaller straight-edges, it may be possible to hold the straight edge by hand without any additional securing device. Applicant's co-pending application Ser. No. 803,616 entitled "Cutting Guide" describes the square with a straight-guiding edge held in position by hand on smaller work stock.
Applicant's U.S. Pat. No. 4,028,976 issued June 14, 1977 entitled "Cutting Tool Guiding System" illustrates the use of pin for fixedly securing the straight-edge to the workpiece during saw guiding operation. It will be appreciated that straight-edges held in place manually are limited in size by the maximum size an individual can easily hold in position by hand. Pinned straight-edges are limited in size by the size a workman can easily carry from job to job and site to site.
There is no prior art device that makes it possible to guide a portable tool such as a circular saw in making cut of extended length. Also there is no prior structure which makes it possible to secure extended length straight edges on surfaces which would be damaged by or which will not permit the penetration of pins as a means for holding the straight-edge in place.
Therefore, it is desirable to have a straight-edge system which may be secured to the surface of a workpiece and provide an extended guiding edge, and which may be broken down into a convenient size for carrying and storage. Such a device is particularly desirable where several sections of the device may be fastened together without elaborate mechanical fasteners and where the setup and breakdown of the system is easily accomplished.